Refactoring: Make IPC::Channel::TakeClientFileDescriptor() a ScopedFD.

ipc/ipc_test_sink.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ipc/ipc_test_sink.h"
 
 #include "ipc/ipc_listener.h"
 #include "ipc/ipc_message.h"
 
 namespace IPC {
@@ skipping 82 matching lines @@
   filter_list_.RemoveObserver(filter);
 }
 
 #if defined(OS_POSIX) && !defined(OS_NACL)
 
 int TestSink::GetClientFileDescriptor() const {
   NOTREACHED();
   return -1;
 }
 
-int TestSink::TakeClientFileDescriptor() {
+base::ScopedFD TestSink::TakeClientFileDescriptor() {
   NOTREACHED();
-  return -1;
+  return base::ScopedFD();
 }
 
 #endif  // defined(OS_POSIX) && !defined(OS_NACL)
 
 }  // namespace IPC